Dynamic Simulation and Testing of the Electrode-Electrolyte Interface of 3-D Stimulating Microelectrodes

Traditional simulations of current distribution for neuralelectrodes have been based on steady-state, resistive-only models that predict severe current crowding at sharp electrode topologies. In contrast, this work presents time-stepping calculations performed with SPICE and ANSYS that can accurately reflect the capacitive behavior of neuralelectrodes. The simulations display that at the electrode-electrolyte interface, the current distribution exhibits a variation of <10%. While current crowding is observed in the solution adjacent to sharp convex edges, the current at these sites is found to be parallel to the electrode surface, and is not expected to contribute to electrode corrosion. Preliminary dissolution studies at 50 muC/cm ² shows an isometric dissolution pattern, confirming the predicted uniform current density